This disclosure relates generally to vascular access devices and methods, including hypodermic needles, catheter assemblies, and devices used with catheter assemblies. Generally, vascular access devices are used for communicating fluid with the vascular system of patients. For example, catheters are used for infusing fluid, such as saline solution, various medicaments, and/or total parenteral nutrition, into a patient, withdrawing blood from a patient, and/or monitoring various parameters of the patient's vascular system.
Intravenous (IV) catheter assemblies are among the various types of vascular access devices. Over-the-needle peripheral IV catheters are a common IV catheter configuration. As its name implies, an over-the-needle catheter is mounted over an introducer needle having a sharp distal tip. The introducer needle is generally a hypodermic needle coupled to a needle assembly to help guide the needle and to facilitate its cooperation with the catheter. At least the inner surface of the distal portion of the catheter tightly engages the outer surface of the needle to prevent peelback of the catheter and thus facilitate insertion of the catheter into the blood vessel. The catheter and the introducer needle are assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from the patient's skin. The catheter and introducer needle are generally inserted at a shallow angle through the patient's skin into a blood vessel.
In order to verify proper placement of the needle and/or catheter in the blood vessel, the clinician generally confirms that there is “flashback” of blood into a flashback chamber associated with a needle assembly. Flashback generally entails the appearance of a small amount of blood which is visible within the needle assembly. This allows a clinician to confirm placement of the catheter within a patient's blood vessel. Once proper placement of the distal tip of the catheter into the blood vessel is confirmed, the clinician may apply pressure to the blood vessel by pressing down on the patient's skin over the blood vessel distal of the introducer needle and the catheter. This finger pressure momentarily occludes the vessel, minimizing further blood flow through the introducer needle and the catheter.
The clinician may then withdraw the introducer needle from the catheter. The introducer needle may be withdrawn into a needle tip shield or needle shield that covers the needle tip and prevents accidental needle sticks. In general, a needle tip shield includes a housing, a sleeve, or other similar device that is designed such that when the needle is withdrawn from the patient, the needle tip will be trapped/captured within the needle tip shield. The purpose of the needle tip shield is to house the tip of the needle in a secure location, thereby reducing the possibility of needle sticks when the needle and needle tip shield are separated properly from the catheter. The catheter, conversely is left in place to provide intravenous access to the patient.
The separation of the needle assembly from the catheter portions of the catheter assembly presents numerous potential hazards to the clinicians and others in the area. As indicated above, there is a risk of accidental needle sticks if the needle tip is not secured properly in a needle tip shield. Additionally, because the needle has been in contact with blood in the patient's vasculature, blood is often present on the exterior of the needle and is often present inside the lumen of the needle. As the needle is withdrawn, there is a risk that this blood will drip from the needle tip or come into contact with other surfaces to expose clinicians and equipment to blood. Additionally, it has been observed that withdrawing a needle from a catheter assembly often imparts energy to the needle assembly, such as by the intentional or unintentional bending forces applied to the needle during removal. This energy has been observed to cause blood to splatter or spray from the needle as the needle wiggles and shakes with stored energy once it is free from the catheter assembly. While prior needle assemblies have provided needle tip shields to reduce the occurrence of needle sticks, these prior enclosures and clips have not sufficiently addressed the risk that clinicians and equipment may be exposed to blood from the needle without experiencing a needle stick. While the problem of blood exposure from needle tips used in over-the-needle catheters is a common problem, blood exposure risks are also problematic in other uses of hypodermic needles where the needle tip has been in contact with blood. The present disclosure presents systems and methods to significantly limit and/or prevent such blood exposure.